Re: 'is it not the ....'

: My question is related to the use of the construct 'is it not the ...'.

: I hear this most often in parliamentary debate with the phrase 'Is it not the case that ...'.

: Why is the 'not' used?
: Both of the phrases 'Is it the case that ...' and 'Is not the case that ...' can be answered with a Yes or No answer. So I remain confused as to why the more convoluted form is more commonly used.

: Is the 'not' used just to generate a comfortable rhythm to the question?

I've never understood this one either. I await clarification with great interest!